Motor starter



vJune 24, 1930.

H. L. MEEDER MOTOR STARTER Filed July 18, 1929 Patented June 24, 1930 UNITED sra'rrs HERBERT L. MEEDER, 0F DENVER, COLORADO, ASSIGNOR OF TWO-FIFTHS TO BENJAMIN F. PRICE, OF DENVER, COLORADO Moron STARTERy Application filed July 18,

This invention relates to power operated motor starters of the type employed` for starting internal combustion engines and which is intended more particularly-for use in connection with automotive vehicles of all types.

Automobiles and trucks which are driven by internal combustion engines are nearly always provided with an electric starter that Can be used for starting the engine. These starters are operated by power obtained from an electric motor and have a pinion that engages with a ring gear on the flywheell and comprise mechanism that vwill automatically put the pinion in mesh with the ring gear when the motor is started and which will automatically move the pinionvout of mesh as soon as the engine starts running by its own power.

Starters of the type to which reference is made are usually provided with a shaft hav? ing a double pitch square thread with which is connected a pinion having corresponding threads,l The end of the shaft has a collar which is engaged by the pinion and which prevents its removal from the shaft. The threads are arranged so that when the shaft is suddenly rotated by the action of the starting motor, the pinion will remain stationary for a short time duel to its inertia and during'this time it willV be moved towards the ring gear and if the teeth on theV pinion strike the openings between the teeth on the ring gear, the pinion will be moved into operative engagement with the gear and will rotate the latter when its end strikes the flange at theend of the shaft. Vith the type of starter just described, it frequently happens that they teeth of the pinion' strike the ends of the yteeth on the ring gear and owing to the powerful pressure developed by the action of the threaded connection between thepinionand the shaft,

. the starter becomes locked and will also hold the engine against rotation. These starter locks are vvery annoying when they occur and before the parts can be released, it is frequently necessary to remove the starter motor and when this is not done, sufficient 1929. Serial N0. 379,214.

force is applied to shear portions of the teeth to thereby obtain a release.

It is the object of this invention to produce a starter mechanism that shall be s0 constructed that there will be no danger of locking the starter and the engine if the teeth on the pinion should happen to strike the ends of the teeth on the gear.

This invention, briefly described, comprises a cylindrical driving member on the outer surface of which is rotatably mounted a pinion. Secured to the pinion i-s a sleeve that is connected to the driving member by means comprising a helical groove in one and a pin in the other so as to produce in effect a threaded engagement between the 'driving member and the sleeve. The sleeve has a radial fiange kthat extends outwardly and which is connected with the pinion by means of a` friction device that will rotate the pinion whenever the sleeve is rotated, but which will also permit the sleeve to rotate independently of the pinion when the force requiredto rotate the pinion exceeds a predetermined value. The end of the driving member and the end of the pinion are provided with interengaging teeth that prevent relative rotation in one direction, but permits the pinion to be rotated on the driving member in the other direction. Owing to the friction connection between the -sleeve and the pinion, the latter will notfjam or bind when it strikes the side o f the ring gear and cannot stick ory lock.

Having thus briefly described the invention, the same will now be described in detail, and for this purpose reference will be had to the accompanying drawing in which the preferred embodiment thereof has been illustrated, and in which: Y

Fig. l is a plan view of the mechanism forming the subject of this invention, portions being broken away to better'disclose the construction;

Fig. 2 is a section taken on line 2 2,

Fig. l Y

Fig. 3 is a section taken on line 3 3, Fig. 2; Fig. 4; is a view of the end of the driving member; and

rthe manner Fig. 5 is a section taken on line 2--2, and n shows the manner of securing the pin and roller to the d 1iving member.

1n the drawing reference numeral 1 represents the motor shaft which is rotated by means of the starting motor which has not been shown. Secured to the shaft so as to be held against movement relative thereto, is a ring 2, to which one end of the starter spring' 3 is .connected by means of a bolt Ll'. Secured en the drive shaft so that it may have both longitudinal and rotary motion with respect thereto, is a tubular cylindrical driving member 5. @ne end of this member is provided with a. plurality of spaced teeth 6 whose rear surfaces 7 are arched in the manner showninrFig. Il and whose front surfaces S are inclined. A pinion 9 is rotatably mounted on member 5. The front end of this pinion is provided with teeth 10 that are adapted to interengage with teeth 6 in shown in Fig. 1. The rear end of pinion 9 has secured thereto a ring 11 which has a cylindrical flange 12 extending rearwardly in the manner shown in Fig. 2. r1`his ring is held in place by means of threaded pins l3- that are located in holes drilled partly in the material of the pinion and partly in the material of the ring. The flange 12 is provided on its inner surface with a. groove 14 for the reception ofV the outer edge of the spring ring Y15, to which attention will be hereinafter more particularly directed. Asleeve 16 is mounted for rotation on nember 5 and has an outwardly extending flange 17 Vthat fits within the circular recess in ring 11. The spring ring is provided with a plurality of resilient tongues 17 that engage the surface of the flange and serve to produce sufficient friction to enable the sleeve to rotate the pinion. ileeve 16 Vis provided on its inner surface with two helical grooves 18. The driving member 5 is provided with two pins 19 that are located diametrically opposite from each otherl and which each carries a roller 20. These pins have their inner ends threaded as 1 indicated by 21 and areheld against rotation by means of stoel pins 22 that in turn are held against, longitudinal movement by the metal 23 which is peaned over the ends of the pins. Therollers 2OV are of such diameter that they will fit the grooves 18 in the manner shown most clearly in Fig. V1. The grooves 18 andV rollers 2O form what is in effect a threaded engagement between the, sleeve and the driving member and where space will permit, it is possible to substitute for the interconnecting means just described an ordinary doub'lepitch square thread and the means employed should therefore be cony strued as a species of threaded engagement whose purposeis to produce positive longitudinal movement when the parts rotate relative to each other. Secured to the rear end of member 5 is a collar 24, which is held in place by means of a key 25 and a screw 26. his collar has an outwardly extending flange or projection 27 which is provided with a radial opening for the reception of the screw 28. The inner surface of flange 27 is spaced from the outer surface of member 5 a sufhcient distance to receive the end of sleeve 16. The purpose of the overhanging construction just described is to shorten the length of the apparatus, but can be dispensed with whenever sufficient space is available. A starter spring 3 has its end 29 connected with the collar 2 by meansof the bolt 4l and has its other end 30 connected with the flange 27 by means of screw 28.V The purpose of the spring iste absorb any shock due to the sudden engagement of the pinion with the ring gear 81. f

Vith the partsr assembled in the manner described, let us assume that shaft 1 is the drive shaft of a motor and that the motor is started so as to rotate the ring 2 in the direction of the arrow in Fig. 1. The motion of ring 2 will be immediately transfe Tred to the flange 27 through the spring 3 and this, in turn, will rotate thedriving member 5. Owing to the inertia of the pinion and the sleeve, relative movement will be set up between these parts and the driving member with the result that they Will be moved towards the left from the position shown in Fig. 2. 1f the teeth on the pinion strike the spaces between the teeth Yon gear 31, the pinion will continue to move towards the left until the teeth l0 interengage with the teeth 6 on member 5`. And when this occurs the further rotation of member 5 will cause the gear 31 to rotate. 1f the teeth on the pinion should strike the teeth on the gear instead of the spaces between the teeth, the further movement of the pinion towards the left would be prevented, but if this occurs the sleeve v16 will begin to rotate with respect to the pinion and therefore the threaded connection between the sleeve and member 5 will not be effective for producing any great amount of force and the pinion will therefore not jam in the manner in which it does whenA the pinion itself is threadedly connected with the driving member.

lt will be seen from the above that `on account of the friction drive between the sleeve and the pinion all dangerL of locking the starter or of bending and breaking the ring gear is obviated( f y nHaving described my invention what I claim as new is:

y1'. A power operated motor starter comprising, in combination, a driving member adapted to be rotated, a pinion mounted for rotation thereon, a sleeve carried by the driving member, the inner (surfaceY of the sleeve having a helical groove, a `pin project.-

ing outwardly from the driving member for engagement With the sides of the groove, one end of the sleeve having a radial flange at one end, the pinion having a'ciroular recess at one end which is adapted to receive the flange of the sleeve, a removable spring ring for holding the flange in the recess, friction means between the pinion and the iiange, and interengaging lugs on the pinion and the driving member for holding them against relative rotation When the pinion isin a predetermined position.

2. A power operated motor starter comprising, in combination, a driving member adapted to be rotated, a sleeve carried by the driving member7 means for interconnecting said members, said means comprising a helical groove in one member and a cooperating projection on the other member, a pinion carried on the driving member, a friction connection between the sleeve and the pinion, and interengaging lugs on the pinion and the driving member for holding them against rotation in one direction When the pinion is in a predetermined position.

In testimony whereof I ailiX my signature.

HERBERT L. MEEDER. 

